From: info@turneraudio.com.au   
      
   I've been asked by a couple of locals in my town to make their guitar amps   
   sound better. One has had 20 years as a working muso and the other teaches   
   music and plays at gigs often. d    
   How they perceive sound is often difficult. It varies between individuals, and   
   if I had a cent for each time I heard musicians talk about amp sound quality,   
   or for each time I read utter BS about guitar amps online,   
   and all without the slightest technical appraisals, I'd be STOINKINGLY RICH!   
   The teacher said he had a slight buzz from one amp he brought, and it wasn't   
   obvious, but sure enough there was a loose spade connector on one of two   
   speakers in the cab.     
      
   But a month ago one customer brought in an old 1965 amp plus his guitar, and   
   demoed to me why he liked it in comparison to a newly made Fender re-issue of   
   the same model number. The re-issue he said, was bloody awful, and indeed even   
   my tired old ears    
   could hear exactly what he was saying about the sound. The 1965 sound was just   
   so much better than the 2013 sound.   
      
   So I explored F response. Its anything but flat, and it seems the best sound   
   comes when the response shows 100Hz at say 0dB, then a dip in response of -5dB   
   at 400Hz, then rising to 0dB by 1kHz and rising at 6dB/octave above 1kHz to   
   5kHz, then ending op    
   at 0dB at 20kHz.    
      
   For most guitar amps, if the controls are adjusted widely for the best square   
   wave possible 1kHz, usually it sounds dull and lifeless. So flatness in   
   response isn't wanted.    
      
   I came across the tone control calculator at Duncan's amp pages.   
   Its the best attempt at such a thing I have seen, but after building a couple   
   of sample "tone stacks" and measuring the responses, I often could not get the   
   same curves. In general, Duncan's tone stack calculator gives far more   
   optimistic boost and cut    
   than appears to be possible, and there does not seem to be adequate means of   
   inputting the measured resistance of pots used in the 1, 5 and 10 positions,   
   so one doesn't know what effect a log A or log B pot might have, or what   
   assumptions about pot have    
   been made by the program.   
      
   Remarkably, many guitar amps have very poor F response with inadequate bass   
   levels and no way of much boosting them much. Sound is tinny, harsh. There's   
   poor treble boost, and almost non existent benefit of a "middle" which if at   
   least done basically,    
   should be able to create a -10dB dip at between 320Hz and 1,000Hz which seems   
   to give the best sound, by amplifying the highest string harmonics the most.   
      
   Is there a better calculator around for tone controls which allows any   
   combination of R&C to be used? I don't wish to use a circuit simulation   
   program.    
      
   I have the offending Fender Deluxe on my and will eventually figure a decent   
   mod so it sounds better - I hope - and as a result of applied science rather   
   than applied BS.   
      
   Patrick Turner   
      
   --- SoupGate-Win32 v1.05   
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